1. Field of the Invention
The present invention relates to a laser module device, and in particular, to a laser module device which can adjust the inclination angles of a laser generator that emits a laser beam, and of a cylindrical lens that receives the laser beam.
2. Description of the Prior Art
The laser is a remarkable invention in modern science. The theory of generating laser light is as follows. According to Bohr's atomic theory, the electrons distributed around atoms or molecules all have a certain energy. The energy of an electron is the sum of its kinetic energy and potential energy, and can only be located at a specific energy level among a series of discontinuous separate energy levels. The state with the lowest energy is called the ground state (low-energy state). Although most electrons are usually in the ground state with the lowest energy in a state of thermal equilibrium, when energy in any form (heat, light, electricity, chemical effect, etc.) is added from outside to the electrons in the ground state, the electrons will be excited and move to a higher-energy state (excited state). The excited state is not stable and has a tendency to return to the low-energy state. At that time, the electrons at the higher energy level will fall back to the ground state due to stimulated emission, and release the excess energy at the same time. The excess energy will be converted to hv (h: Planck constant, v: light frequency), that is, the so-called light quantum or photon. If the electrons stay in the excited state longer than the time that they stay in the ground state, or if many particles at the low energy level can be moved to a higher-energy level in a very short period of time, and if the electrons in the excited state generate stimulated emission (high energy level/low energy level) that is accompanied with the release of photons at the same time, it is possible to generate a large quantity of light with the same orientation, the same frequency, and the same phase if the light is amplified repeatedly by a back-coupling mechanism. This is the basic theory of generating a laser beam.
A laser module includes a laser unit used for generating a laser beam, and a corresponding control circuit. With the aid of a lens, this device can generate a highly-collimated laser beam. The laser module has therefore been used widely in various application fields. For example, the popular laser pointer is formed by adding a laser module at the front end of a pen body. The laser beam generated by the laser module can form a very bright light spot on an object for instructional purposes. In addition, a laser module can also be used for a collimator, level meter, laser projector, etc.
FIGS. 1A and 1B illustrate the structure of a conventional laser module. A conventional laser module 1 has a hollow cylindrical structure as a housing space 11. A laser generator 12 and a cylindrical lens 13 are respectively connected to the opposite ends of the housing space 11. A convex lens 15 is positioned in the middle of the housing space 11 between the laser generator 12 and the lens 13. After the device is turned on, laser generator 12 will emit a laser beam. The laser beam becomes parallel after passing through the housing space 11 and the convex lens 15. The light beam then reaches cylindrical lens 13 where it is refracted. A light shield 14 can be used to eliminate parasitic light to provide a linear laser beam for use. However, deviation usually occurs in the mounting angle of the laser generator 12 when it is connected inside the housing space 11. As a result, the laser beam does not travel along the central axis 16 of the housing spacing 11, resulting in deviation in the angle of incidence on the cylindrical lens 13. Alternatively, if there is deviation in the mounting angle of the cylindrical lens 13 when it is mounted inside housing space 11, the laser beam will lose most of its energy after it is refracted by the cylindrical lens 13. As a result, a relatively short or weak linear laser beam, or a laser beam with relatively large curvature, will be generated. Such laser beams will not meet the user's requirements.
Consequently, there is a need for improved laser modules which overcome the drawbacks described above.